Angular2 - ngIf在ng

Question

我想检查实际元素是否有值。

例如，我想检查巧克力是黑色还是白色。根据这一点，我想显示正确的文字。

<ng-container *ngFor="let chocolate of product.getChocolates();">
     <md-card *ngIf="chocolate.getName() == black">IT IS BLACK</md-card>
     <md-card *ngIf="chocolate.getName() == white">IT IS WHITE</md-card>
</ng-container>

如何修复代码，以便它可以正常工作？

Answer 1

问题是您错过'（单引号）string后面black＆amp; white

<ng-container *ngFor="let chocolate of product.getChocolates();">
     <md-card *ngIf="chocolate.getName() == 'black'">IT IS BLACK</md-card>
     <md-card *ngIf="chocolate.getName() == 'white'">IT IS WHITE</md-card>
</ng-container>

Answer 2

import { Component } from '@angular/core';

@Component({
  selector: 'my-app',
  template: `<div *ngFor="let chocolate of chocolates">
     <div *ngIf="chocolate.name == 'black'">IT IS BLACK</div>
     <div *ngIf="chocolate.name == 'white'">IT IS WHITE</div>
</div>`
})
export class AppComponent{
  chocolates:any=[{
    name:'black'
  },
  {
    name:'white'
  }];

  constructor() { }
}

Answer 3

<ng-container *ngFor="let chocolate of product.getChocolates();">
     <md-card *ngIf="chocolate.getName() == black">IT IS BLACK</md-card>
     <md-card *ngIf="chocolate.getName() == white">IT IS WHITE</md-card>
</ng-container>

将chocolate .getName()修改为chocolate.getName()